In recent years, a bronchoscope has widely been used in which an elongated insertion part is inserted into a body cavity, to thereby observe an inspection objective part within the body cavity without the necessity of incision or excision and, under certain circumstances, to thereby use a treatment tool, e.g., needle, so as to be able one to perform therapy and treatment.
The insertion part of the bronchoscope is so arranged as to have flexibility so as to be capable of being inserted into a bent or curved insertion path. Because the insertion part of the bronchoscope can have arduous curves used within the airways, the treatment tool, such as a needle, needs to have equal flexibility. However, if the treatment tool is too flexible, it may be ineffective when exposed outside of the insertion part of the bronchoscope. But, a needle flexible enough to navigate the arduous curves may not have enough translational stiffness for sampling.